diff options
Diffstat (limited to 'crypto/heimdal/lib/kafs/dlfcn.c')
| -rw-r--r-- | crypto/heimdal/lib/kafs/dlfcn.c | 581 |
1 files changed, 581 insertions, 0 deletions
diff --git a/crypto/heimdal/lib/kafs/dlfcn.c b/crypto/heimdal/lib/kafs/dlfcn.c new file mode 100644 index 0000000..e664fe3 --- /dev/null +++ b/crypto/heimdal/lib/kafs/dlfcn.c @@ -0,0 +1,581 @@ +/* + * @(#)dlfcn.c 1.11 revision of 96/04/10 20:12:51 + * This is an unpublished work copyright (c) 1992 HELIOS Software GmbH + * 30159 Hannover, Germany + */ + +/* + * Changes marked with `--jwe' were made on April 7 1996 by John W. Eaton + * <jwe@bevo.che.wisc.edu> to support g++ and/or use with Octave. + */ + +/* + * This makes my life easier with Octave. --jwe + */ +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#include <stdio.h> +#include <errno.h> +#include <string.h> +#include <stdlib.h> +#include <sys/types.h> +#include <sys/ldr.h> +#include <a.out.h> +#include <ldfcn.h> +#include "dlfcn.h" + +/* + * We simulate dlopen() et al. through a call to load. Because AIX has + * no call to find an exported symbol we read the loader section of the + * loaded module and build a list of exported symbols and their virtual + * address. + */ + +typedef struct { + char *name; /* the symbols's name */ + void *addr; /* its relocated virtual address */ +} Export, *ExportPtr; + +/* + * xlC uses the following structure to list its constructors and + * destructors. This is gleaned from the output of munch. + */ +typedef struct { + void (*init)(void); /* call static constructors */ + void (*term)(void); /* call static destructors */ +} Cdtor, *CdtorPtr; + +typedef void (*GccCDtorPtr)(void); + +/* + * The void * handle returned from dlopen is actually a ModulePtr. + */ +typedef struct Module { + struct Module *next; + char *name; /* module name for refcounting */ + int refCnt; /* the number of references */ + void *entry; /* entry point from load */ + struct dl_info *info; /* optional init/terminate functions */ + CdtorPtr cdtors; /* optional C++ constructors */ + GccCDtorPtr gcc_ctor; /* g++ constructors --jwe */ + GccCDtorPtr gcc_dtor; /* g++ destructors --jwe */ + int nExports; /* the number of exports found */ + ExportPtr exports; /* the array of exports */ +} Module, *ModulePtr; + +/* + * We keep a list of all loaded modules to be able to call the fini + * handlers and destructors at atexit() time. + */ +static ModulePtr modList; + +/* + * The last error from one of the dl* routines is kept in static + * variables here. Each error is returned only once to the caller. + */ +static char errbuf[BUFSIZ]; +static int errvalid; + +/* + * The `fixed' gcc header files on AIX 3.2.5 provide a prototype for + * strdup(). --jwe + */ +#ifndef HAVE_STRDUP +extern char *strdup(const char *); +#endif +static void caterr(char *); +static int readExports(ModulePtr); +static void terminate(void); +static void *findMain(void); + +void *dlopen(const char *path, int mode) +{ + ModulePtr mp; + static void *mainModule; + + /* + * Upon the first call register a terminate handler that will + * close all libraries. Also get a reference to the main module + * for use with loadbind. + */ + if (!mainModule) { + if ((mainModule = findMain()) == NULL) + return NULL; + atexit(terminate); + } + /* + * Scan the list of modules if we have the module already loaded. + */ + for (mp = modList; mp; mp = mp->next) + if (strcmp(mp->name, path) == 0) { + mp->refCnt++; + return mp; + } + if ((mp = (ModulePtr)calloc(1, sizeof(*mp))) == NULL) { + errvalid++; + snprintf (errbuf, "calloc: %s", strerror(errno)); + return NULL; + } + if ((mp->name = strdup(path)) == NULL) { + errvalid++; + snprintf (errbuf, "strdup: %s", strerror(errno)); + free(mp); + return NULL; + } + /* + * load should be declared load(const char *...). Thus we + * cast the path to a normal char *. Ugly. + */ + if ((mp->entry = (void *)load((char *)path, L_NOAUTODEFER, NULL)) == NULL) { + free(mp->name); + free(mp); + errvalid++; + snprintf (errbuf, sizeof(errbuf), + "dlopen: %s: ", path); + /* + * If AIX says the file is not executable, the error + * can be further described by querying the loader about + * the last error. + */ + if (errno == ENOEXEC) { + char *tmp[BUFSIZ/sizeof(char *)]; + if (loadquery(L_GETMESSAGES, tmp, sizeof(tmp)) == -1) + strlcpy(errbuf, + strerror(errno), + sizeof(errbuf)); + else { + char **p; + for (p = tmp; *p; p++) + caterr(*p); + } + } else + strlcat(errbuf, + strerror(errno), + sizeof(errbuf)); + return NULL; + } + mp->refCnt = 1; + mp->next = modList; + modList = mp; + if (loadbind(0, mainModule, mp->entry) == -1) { + dlclose(mp); + errvalid++; + snprintf (errbuf, sizeof(errbuf), + "loadbind: %s", strerror(errno)); + return NULL; + } + /* + * If the user wants global binding, loadbind against all other + * loaded modules. + */ + if (mode & RTLD_GLOBAL) { + ModulePtr mp1; + for (mp1 = mp->next; mp1; mp1 = mp1->next) + if (loadbind(0, mp1->entry, mp->entry) == -1) { + dlclose(mp); + errvalid++; + snprintf (errbuf, sizeof(errbuf), + "loadbind: %s", + strerror(errno)); + return NULL; + } + } + if (readExports(mp) == -1) { + dlclose(mp); + return NULL; + } + /* + * If there is a dl_info structure, call the init function. + */ + if (mp->info = (struct dl_info *)dlsym(mp, "dl_info")) { + if (mp->info->init) + (*mp->info->init)(); + } else + errvalid = 0; + /* + * If the shared object was compiled using xlC we will need + * to call static constructors (and later on dlclose destructors). + */ + if (mp->cdtors = (CdtorPtr)dlsym(mp, "__cdtors")) { + CdtorPtr cp = mp->cdtors; + while (cp->init || cp->term) { + if (cp->init && cp->init != (void (*)(void))0xffffffff) + (*cp->init)(); + cp++; + } + /* + * If the shared object was compiled using g++, we will need + * to call global constructors using the _GLOBAL__DI function, + * and later, global destructors using the _GLOBAL_DD + * funciton. --jwe + */ + } else if (mp->gcc_ctor = (GccCDtorPtr)dlsym(mp, "_GLOBAL__DI")) { + (*mp->gcc_ctor)(); + mp->gcc_dtor = (GccCDtorPtr)dlsym(mp, "_GLOBAL__DD"); + } else + errvalid = 0; + return mp; +} + +/* + * Attempt to decipher an AIX loader error message and append it + * to our static error message buffer. + */ +static void caterr(char *s) +{ + char *p = s; + + while (*p >= '0' && *p <= '9') + p++; + switch(atoi(s)) { + case L_ERROR_TOOMANY: + strlcat(errbuf, "to many errors", sizeof(errbuf)); + break; + case L_ERROR_NOLIB: + strlcat(errbuf, "can't load library", sizeof(errbuf)); + strlcat(errbuf, p, sizeof(errbuf)); + break; + case L_ERROR_UNDEF: + strlcat(errbuf, "can't find symbol", sizeof(errbuf)); + strlcat(errbuf, p, sizeof(errbuf)); + break; + case L_ERROR_RLDBAD: + strlcat(errbuf, "bad RLD", sizeof(errbuf)); + strlcat(errbuf, p, sizeof(errbuf)); + break; + case L_ERROR_FORMAT: + strlcat(errbuf, "bad exec format in", sizeof(errbuf)); + strlcat(errbuf, p, sizeof(errbuf)); + break; + case L_ERROR_ERRNO: + strlcat(errbuf, strerror(atoi(++p)), sizeof(errbuf)); + break; + default: + strlcat(errbuf, s, sizeof(errbuf)); + break; + } +} + +void *dlsym(void *handle, const char *symbol) +{ + ModulePtr mp = (ModulePtr)handle; + ExportPtr ep; + int i; + + /* + * Could speed up the search, but I assume that one assigns + * the result to function pointers anyways. + */ + for (ep = mp->exports, i = mp->nExports; i; i--, ep++) + if (strcmp(ep->name, symbol) == 0) + return ep->addr; + errvalid++; + snprintf (errbuf, sizeof(errbuf), + "dlsym: undefined symbol %s", symbol); + return NULL; +} + +char *dlerror(void) +{ + if (errvalid) { + errvalid = 0; + return errbuf; + } + return NULL; +} + +int dlclose(void *handle) +{ + ModulePtr mp = (ModulePtr)handle; + int result; + ModulePtr mp1; + + if (--mp->refCnt > 0) + return 0; + if (mp->info && mp->info->fini) + (*mp->info->fini)(); + if (mp->cdtors) { + CdtorPtr cp = mp->cdtors; + while (cp->init || cp->term) { + if (cp->term && cp->init != (void (*)(void))0xffffffff) + (*cp->term)(); + cp++; + } + /* + * If the function to handle global destructors for g++ + * exists, call it. --jwe + */ + } else if (mp->gcc_dtor) { + (*mp->gcc_dtor)(); + } + result = unload(mp->entry); + if (result == -1) { + errvalid++; + snprintf (errbuf, sizeof(errbuf), + "%s", strerror(errno)); + } + if (mp->exports) { + ExportPtr ep; + int i; + for (ep = mp->exports, i = mp->nExports; i; i--, ep++) + if (ep->name) + free(ep->name); + free(mp->exports); + } + if (mp == modList) + modList = mp->next; + else { + for (mp1 = modList; mp1; mp1 = mp1->next) + if (mp1->next == mp) { + mp1->next = mp->next; + break; + } + } + free(mp->name); + free(mp); + return result; +} + +static void terminate(void) +{ + while (modList) + dlclose(modList); +} + +/* + * Build the export table from the XCOFF .loader section. + */ +static int readExports(ModulePtr mp) +{ + LDFILE *ldp = NULL; + SCNHDR sh, shdata; + LDHDR *lhp; + char *ldbuf; + LDSYM *ls; + int i; + ExportPtr ep; + + if ((ldp = ldopen(mp->name, ldp)) == NULL) { + struct ld_info *lp; + char *buf; + int size = 4*1024; + if (errno != ENOENT) { + errvalid++; + snprintf(errbuf, sizeof(errbuf), + "readExports: %s", + strerror(errno)); + return -1; + } + /* + * The module might be loaded due to the LIBPATH + * environment variable. Search for the loaded + * module using L_GETINFO. + */ + if ((buf = malloc(size)) == NULL) { + errvalid++; + snprintf(errbuf, sizeof(errbuf), + "readExports: %s", + strerror(errno)); + return -1; + } + while ((i = loadquery(L_GETINFO, buf, size)) == -1 && errno == ENOMEM) { + free(buf); + size += 4*1024; + if ((buf = malloc(size)) == NULL) { + errvalid++; + snprintf(errbuf, sizeof(errbuf), + "readExports: %s", + strerror(errno)); + return -1; + } + } + if (i == -1) { + errvalid++; + snprintf(errbuf, sizeof(errbuf), + "readExports: %s", + strerror(errno)); + free(buf); + return -1; + } + /* + * Traverse the list of loaded modules. The entry point + * returned by load() does actually point to the data + * segment origin. + */ + lp = (struct ld_info *)buf; + while (lp) { + if (lp->ldinfo_dataorg == mp->entry) { + ldp = ldopen(lp->ldinfo_filename, ldp); + break; + } + if (lp->ldinfo_next == 0) + lp = NULL; + else + lp = (struct ld_info *)((char *)lp + lp->ldinfo_next); + } + free(buf); + if (!ldp) { + errvalid++; + snprintf (errbuf, sizeof(errbuf), + "readExports: %s", strerror(errno)); + return -1; + } + } + if (TYPE(ldp) != U802TOCMAGIC) { + errvalid++; + snprintf(errbuf, sizeof(errbuf), "readExports: bad magic"); + while(ldclose(ldp) == FAILURE) + ; + return -1; + } + /* + * Get the padding for the data section. This is needed for + * AIX 4.1 compilers. This is used when building the final + * function pointer to the exported symbol. + */ + if (ldnshread(ldp, _DATA, &shdata) != SUCCESS) { + errvalid++; + snprintf(errbuf, sizeof(errbuf), + "readExports: cannot read data section header"); + while(ldclose(ldp) == FAILURE) + ; + return -1; + } + if (ldnshread(ldp, _LOADER, &sh) != SUCCESS) { + errvalid++; + snprintf(errbuf, sizeof(errbuf), + "readExports: cannot read loader section header"); + while(ldclose(ldp) == FAILURE) + ; + return -1; + } + /* + * We read the complete loader section in one chunk, this makes + * finding long symbol names residing in the string table easier. + */ + if ((ldbuf = (char *)malloc(sh.s_size)) == NULL) { + errvalid++; + snprintf (errbuf, sizeof(errbuf), + "readExports: %s", strerror(errno)); + while(ldclose(ldp) == FAILURE) + ; + return -1; + } + if (FSEEK(ldp, sh.s_scnptr, BEGINNING) != OKFSEEK) { + errvalid++; + snprintf(errbuf, sizeof(errbuf), + "readExports: cannot seek to loader section"); + free(ldbuf); + while(ldclose(ldp) == FAILURE) + ; + return -1; + } + if (FREAD(ldbuf, sh.s_size, 1, ldp) != 1) { + errvalid++; + snprintf(errbuf, sizeof(errbuf), + "readExports: cannot read loader section"); + free(ldbuf); + while(ldclose(ldp) == FAILURE) + ; + return -1; + } + lhp = (LDHDR *)ldbuf; + ls = (LDSYM *)(ldbuf+LDHDRSZ); + /* + * Count the number of exports to include in our export table. + */ + for (i = lhp->l_nsyms; i; i--, ls++) { + if (!LDR_EXPORT(*ls)) + continue; + mp->nExports++; + } + if ((mp->exports = (ExportPtr)calloc(mp->nExports, sizeof(*mp->exports))) == NULL) { + errvalid++; + snprintf (errbuf, sizeof(errbuf), + "readExports: %s", strerror(errno)); + free(ldbuf); + while(ldclose(ldp) == FAILURE) + ; + return -1; + } + /* + * Fill in the export table. All entries are relative to + * the entry point we got from load. + */ + ep = mp->exports; + ls = (LDSYM *)(ldbuf+LDHDRSZ); + for (i = lhp->l_nsyms; i; i--, ls++) { + char *symname; + char tmpsym[SYMNMLEN+1]; + if (!LDR_EXPORT(*ls)) + continue; + if (ls->l_zeroes == 0) + symname = ls->l_offset+lhp->l_stoff+ldbuf; + else { + /* + * The l_name member is not zero terminated, we + * must copy the first SYMNMLEN chars and make + * sure we have a zero byte at the end. + */ + strlcpy (tmpsym, ls->l_name, + SYMNMLEN + 1); + symname = tmpsym; + } + ep->name = strdup(symname); + ep->addr = (void *)((unsigned long)mp->entry + + ls->l_value - shdata.s_vaddr); + ep++; + } + free(ldbuf); + while(ldclose(ldp) == FAILURE) + ; + return 0; +} + +/* + * Find the main modules entry point. This is used as export pointer + * for loadbind() to be able to resolve references to the main part. + */ +static void * findMain(void) +{ + struct ld_info *lp; + char *buf; + int size = 4*1024; + int i; + void *ret; + + if ((buf = malloc(size)) == NULL) { + errvalid++; + snprintf (errbuf, sizeof(errbuf), + "findMail: %s", strerror(errno)); + return NULL; + } + while ((i = loadquery(L_GETINFO, buf, size)) == -1 && errno == ENOMEM) { + free(buf); + size += 4*1024; + if ((buf = malloc(size)) == NULL) { + errvalid++; + snprintf (errbuf, sizeof(errbuf), + "findMail: %s", strerror(errno)); + return NULL; + } + } + if (i == -1) { + errvalid++; + snprintf (errbuf, sizeof(errbuf), + "findMail: %s", strerror(errno)); + free(buf); + return NULL; + } + /* + * The first entry is the main module. The entry point + * returned by load() does actually point to the data + * segment origin. + */ + lp = (struct ld_info *)buf; + ret = lp->ldinfo_dataorg; + free(buf); + return ret; +} |
